Dataset contains hydrochemistry data from the Romanian inner shelf waters (bottom depths between 17 and 149 m). Data were collected on board R/V Mare Nigrum, during a cruise conducted in July 2023, within the national project "Improving the monitoring program for the Romanian Black Sea self in order to increase the capacity to assess and predict the impact of multistressors on marine ecosystem services" PN 23 30 01 03". Twenty-six stations distributed along 3 main transects (Sf. Gheorghe-SE, Portita-SE, and Constanta-SE) were performed for water column investigations by the GeoEcoMar team. In situ measurements of physical-chemical seawater parameters were done at each sampling station using a CTD SBE 25, with SBE 32 rosette. Seawater samples were collected with 5L Niskin bottles from different depths and further analyzed in the GeoEcoMar lab for nutrients, chlorophylls and phaeophytin, TOC, and heavy metals.